Sensor for detecting marks on moving articles

ABSTRACT

In the order of the numerical value of the zip code, a counter and stacker device for signatures, such as magazines, newspapers, and the like, wherein changes in zip code are identified by a mark. The signatures are carried in alignment away from a label applicator by a conveyor belt. The inventive circuit senses the mark indicating code change and causes a kicker to change the alignment of the first signature carrying a label with a new zip code.

Ullltfid States Patent 11 1 1111 3,839,636

Worrall Oct. 1, 1974 SENSOR FOR DETECTING MARKS 0N 3,411,008 11/1968Coombes et al 250/219 or MOVING ARTICLES 3,739,181 6/1973 Vincent, Jr.et al. 250/223 R X Inventor:

John L. Worrall, Wheeling, 111.

Filed: Mar. 5, 1973 Appl. No.: 338,130

Assignee:

US. Cl 250/223 R, 209/DIG. 1, 250/555 Int. Cl. G06m 7/00 Field of Search..250/2l9 DF, 219 DQ. 219 DR, 250/223 R. 555. 556. 557; 209/DIG. 1.111.7

References Cited UNITED STATES PATENTS 6/1940 Gulliksen 250/219 DR5/1960 Harmon 250/219 DO X Primary Examiner-Walter Stolwein Attorney,Agent, or FirmRobert A. Walsh; Gerald B. Epstein l5 7] ABSTRACT In theorder of the numerical value of the zip code, a counter and stackerdevice for signatures, such as magazines, newspapers, and the like,wherein changes in zip code are identified by a mark. The signatures arecarried in alignment away from a label applicator by a conveyor belt.The inventive circuit senses the mark indicating code change and causesa kicker to change the alignment of the first signature carrying a labelwith a new zip code.

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AWN

SENSOR FOR DETECTING MARKS ON MOVING ARTICLES This invention relates tomark sensors and, more particularly, although not exclusively, to meansfor detecting changes in zip codes on address labels.

The Post Office has attempted to automate its mail handling capabilitiesby using zip codes which identify postal areas. In an effort to forceusers to show their zip codes, a number of rules and regulations havebeen adopted by the Post Office. Among these rules, the large users ofthe mail are required to prepackage their mail according to the zipcode.

Exemplary of large users are those who mail signatures, such asmagazines and newspapers. These larger users generally employ eitheraddress plates or computer-controlled printers to print the addresslabels. Then, it is necessary to cause the signatures to be stackedaccording to the zip codes on the labels. Thus, either the conveyor atthe output of the printer must be modified or some other means must beprovided for controlling the stacking function.

Accordingly, an object of the invention is to provide new and improvedmeans for recognizing a printed signal. Here an object is to providemeans for sensing a mark on a printed label.

Another object of the invention is to provide mean for assembling thesignatures at the output of a printing press according to the zip codeprintedon a label on the signature. Here an object is to accomplishthese and other objects without substantially modifying the press.

In keeping with an aspect of the invention, a photoelectric cell ispositioned to read a mark on a label as each signature moves down aconveyor at the output of the press. If the mark is present, a kickerisoperated to skew or reposition the pertinent signature on the conveyorline. Then, the signatures may be assembled at the end of the conveyor,in stacks, according to the repositioned signatures.

The nature of a preferred embodiment for accomplishing these and otherobjects may become more apparent from a study of the attached drawingwherein:

FIG. 1 is a schematic representation of the disposition of the novelsensor head of my invention with a head for applying address labels to aseries of signatures;

FIG. 2 schematically represents a series of labels on successivesignatures, indicating how the change in zip coding is sensed; and

7 FIG. 3 is a schematic diagram showing the circuit used to drive thesensor.

The major elements in FIG. 1 are a labeling head 20, a first conveyorbelt 21 at the output of the labeling head 20, a second conveyor belt21', disposed at right angles adjacent the terminal portion of conveyorbelt 20, a kicker 22 adjacent conveyor belt 21 a guard synchronizer 23,a reading or sensor head 24, and a delay circuit 24'. The label head 20may be any suitable device, preferably feeding a plurality of E/Waligned address labels 27 through the head. Each label 27 includes anaddress, including the zip code of the'addressee. The conveyor belt 21conveys any suitable signatures, such as magazine 26, past the labelhead 20, which applies the labels individually to magazines 26, as shownat 35, 36. The signatures are aligned on the conveyor belt with theindividual labels 35, 36 displaced from each other by a uniform distanced. Delay circuit 24 is suitably connected between reader 24 and kicker22 to postpone actuation of the kicker until a magazine 26 containing anew zip code has reached the initial portion of conveyor belt 21'.

The guard device 23 comprises a light-chopping disk 29 which rotates insynchronism with the conveyor belt 21 as indicated by the dashed line30. A window 31 in the light-chopping disk 29 allows light 32 to passfrom lamp 33 to photocell 34. After the disk rotates further, the window31 leaves the position here shown, and the disk cuts the light beam. Itshould be noted that the signatures are located uniformly on theconveyor and that the labels 35, 36 are, therefore, a fixed distance dapart. Accordingly, the drive arrangement 30 may be adjusted to allowlight 32 to reach the photocell 34 only when a label 35 or a portionthereof is under the reader 24. Thus, the guard device inhibits aresponse at all times except when a label is present to be read.

The reader head 24 is shown in FIG. 2 as including a lamp 40 and lens 41mounted to direct a fine ray of light 42 on a particular area on label35 at an angle which reflects the light to a photocell 43. If the labelis essentially white, or other light color, at the point struck by thelight beam 42, there is a high level of current activity in thephotocell 43, and it has a low resistance. However, if the label isessentially black, or other dark color, there is a low level of currentactivity, and the photocell has a high resistance.

The labeling head 20 dispenses labels which are printed with all similarzip codes in linear order. Therefore, all zip codes of the same numberare printed together, as labels having zip code 10000 are shown at 46and labels having zip code 10001 are shown at 47 in FIG. 2. Note that aspecial mark 48 is applied to the label 35 where the zip code changesand that the mark does not appear on succeeding labels. Therefore, ifthe mark 48 is present, the light beam is modified accordingly. Further,the shape of slot 31, size of disk 29, and rotational speed of the diskrelative to the travel speed of the conveyor belt 21 all cooperate toenable the reader 24 so that the photocell 43 is only sensitive to themark when it is present in the path of the beam 42. Hence, any otherprinting on the signature itself is irrelevant.

The electrical circuit driven by the photocells is seen at FIG. 3.Toorient the various figures with respect to each other, note may betaken of the locations of the photocell 43 in reader 24 and photocell 34in the guard synchronizer 23. The principal subdivisons of this circuitare a constant current source 50, a mark reader 51, a guard synchronizer52, an output circuit 53, and a logic control circuit 54.

The constant current source comprises a voltage dividing diode and aresistor 61 connected in series between battery 62 and ground 63. Thediode 60 provides a fixed voltage drop in battery potential forbiasnected directly to ground and the collector of the NPN transistor 71is connected directly to battery.The two base electrodes are connectedtogether and supplied from the constant current source 50. The photocell43 of the mark reader 24 is also connected in common vto the two baseelectrodes of transistors 70, 71. Depending upon the amount of lightfalling on the photocell, its resistance varies to divide the potentialacross battery 62 and ground 75.

In operation, a light reflective material comparable to an unmarkedlabel 46 is placed in the path of light beam 42. The positions of thelabel, lamp and photocell are adjusted, and the potentiometer 65 isadjusted until the resistance of photocell 43 divides the voltagebetween battery 62 and ground 75 to switch on the two transistors 70,71. As soon as transistor 70 switches on, the light-emitting diode 72lights. Then, a label having a mark 48 is placed in the path of the beam42 and the resistance of the photocell 43 increases to change thevoltage division between battery 62 and ground 75. The transistor 70should now switch off. If so, the lightemitting diode 72 goes dark andthe operator knows that adjustments are proper. If not, either theposition of photocell 43 or the potentiometer 65 is readjusted until thediode 72 does go dark. Accordingly, a proper setting is achieved if thediode 72 lights when an unmarked label is present and goes out when amarked label is present.

Since the transistors 70, 71 are connected to behave as a singletransistor, the transistor 71 also switches off and on depending uponthe label marking being sensed by photocell 43.

The guard synchronizer circuit 52 is coupled to the output of the markreader 51 (Le, the emitter of transistor 71) via a resistor 76 and tothe guard photocell 34 via a resistor 77. In greater detail, PNPtriggering transistor 82 has an emitter biased from a voltagedividingpotentiometer 83, a base connected to the coupling resistor 76 and acollector load 84, 85. Transistor 82 turns off when transistor 71 turnson.

The output of the transistor 82 is fed into the base of an NPNtransistor 86 which functions as a driving amplifier. The collector oftransistor 86 is connected through resistor 77 and photocell 34 to abattery. If the disk 29 unmasks the light source 33, the resistance ofphotocell 34 decreases to apply an enabling battery potential toresistor 77.

When transistor 71 turns on, battery is applied to the base of thetransistor 82, and potentiometer 83 is adjusted to turn off transistor82. When transistor 71 turns off, ground is applied to the base of thetransistor 82, and it turns on. I

When transistor 82 turns on the transistor 86 turns on. With transistor86 turned'on, no battery potential appears at its collector, regardlessof the position of disc 29. When transistor 86 is turned off, no batterypotential will appear at its collector until disc 29 is at an angularposition to allow an enabling light to fall on photocell 34.

The diode 90 couples the guard synchronizer circuit 52 from the outputcircuit 53.

Output circuit 53 comprises an NPN transistor 91 having an emitter biasresistor 92 and a collector load resistor 93. A light-emitting diode 94and its series resistor 95 are connected in parallel with load 93. Whenthe transistor 86 turns off to indicate the presence of a zip code mark48, transistor 91 turns on to send a ground signal to control logic 54and to light the lightemitting diode 94. Hence, an operator observingthe lit diode knows that the marker has sensed a zip code mark 48. Thisis primarily useful when the adjustments are originally made atpotentiometers 65 and 83.

A feedback circuit comprising diode and resistor 101 helps stabilize thesystem. The diode 100 is poled to prevent current flow from the emitterof transistor 82 to the collector of transistor 91. As the mark readerstarts to detect a mark or non-mark, there could be a circumstancewherein the circuit might go into selfsustained oscillation. By applyingground potential from the emitter of transistor 91 through diode 100 andthe relatively low resistance 101 to the emitter of transistor 82, theturn-on threshold of transistor 82 is increased. Therefore, the turn-onand turn-off points of transistor 82 are separated, thus eliminating anyoscillatory condition.

In operation, the signatures 26 are aligned on conveyor belt 21 so thatthe signatures pass in a substantially linear direction beneath labelinghead 20. The operator adjusts the position of light 40, the labels 27,photocell 43, and potentiometer 65 until light-emitting diode 72 lights.Then, as a mark passes beneath the photocell, diode 72 should go off toindicate proper setting of photocell 43 and potentiometer 65. If diode72 fails to go off, the positions of these elements is readjusted.

Next, the conveyor belt 21 is set so that the uniform distance d betweenlabels 35, 36 is maintained. The sensor circuit, labeling head 20 andconveyor head 21 are then turned on and the rotative speed of guardsynchronizer 23 is set so that light beam 32 is cut when the zip markregion of the label is not beneath photocell 34. As a mark 48 is beingread, the operator observes light-emitting diode 94 and if it is notlit, adjusts potentiometer 83 until diode 94 is lit.

The output signal at terminal 102, signifying the presence of a zip codemark 48, is applied to any suitable control logic circuitry such asdelay circuit 24' for controlling kicker mechanism 22. Essentially, thiscircuit 24' causes a timing function whereby the signal at terminal 102is delayed until the signature bearing the zip code mark is adjacent thekicker 22. Then, the kicker operates to selectively identify thesignature bearing the mark by knocking askew the signature 104 (F IG. 1)having thereon the label with the zip code mark.

It shall now be apparent that the same zip code appears on allsignatures between two skewed signatures. Thus, it is only necessary toseparate the signatures into stacks identified by the skewed ones. Eachpile may then be addressed to the zip code of a single post office.Still other uses will readily occur to those who are skilled in the art.Therefore, the appended claims are to be construed to cover allequivalent structures falling within the scope and spirit of theinvention.

I claim:

1. A sensor for detecting marks printed at a predetermined region onselective ones of successive label areas formed on each of a pluralityof signatures comprising conveyor means operable for moving saidsignatures in succession, means for scanning each of said successivelabel areas in the region of said marks, guard synchronizing meansresponsive to said conveyer means for selectively controlling saidscanning means each time that said region on a label is being scanned,means responsive to said guard means for enabling said scanning means,and means responsive to a detection of a mark during said enablement ofsaid scanning means for giving an output signal.

2. The sensor of claim 1 including means responsive to said outputsignal for kicking askew the signature bearing said detected mark.

3. The sensor of claim 2 wherein said guard synchronizing meanscomprises a light-chopping means coupled to move in synchronismwith-said conveyor.

4. The sensor of claim 1 and feedback means for precluding more than oneoutput signal response to a sin gle mark.

5. A code mark reader comprising means for providing successive labelsin a predetermined order, said labels being selectively marked at apredetermined place when said order includes a significant change, meansfor applying each label to a different signature, means for reading eachlabel at said predetermined place to detect said selective mark, andmeans responsive to a detection of said mark for selectively identifyingthe label bearing said mark.

6. The reader of claim 5 wherein said code mark is a zip code mark andsaid significant change is a change in a zip code.

7. The reader of claim 6 wherein said mark changes the reflectivity ofsaid label and said reading means comprises a photocell for detectingsaid change in reflectivity.

8. The reader of claim 7 including means for conveying said signaturesin alignment past said reader, and said means for identifying said labelcomprises means for kicking askew the signature having the label bearingsaid mark.

9. The sensor of claim 2 wherein said kicking means includes a delaycircuit to postpone actuation.

10. The sensor of claim 1 wherein said scanning means includes aphotocell.

11. The sensor of claim 1 which includes a visual indicator responsiveto said output signal.

12. The reader of claim 5 wherein reading means is responsive to saidconveyer means.

1. A sensor for detecting marks printed at a predetermined region onselective ones of successive label areas formed on each of a pluralityof signatures comprising conveyor means operable for moving saidsignatures in succession, means for scanning each of said successivelabel areas in the region of said marks, guard synchronizing meansresponsive to said conveyer means for selectively controlling saidscanning means each time that said region on a label is being scanned,means responsive to said guard means for enabling said scanning means,and means responsive to a detection of a mark during said enablement ofsaid scanning means for giving an output signal.
 2. The sensor of claim1 including means responsive to said output signal for kicking askew thesignature bearing said detected mark.
 3. The sensor of claim 2 whereinsaid guard synchronizing means comprises a light-chopping means coupledto move in synchronism with said conveyor.
 4. The sensor of claim 1 andfeedback means for precluding more than one output signal response to asingle mark.
 5. A code mark reader comprising means for providingsuccessive labels in a predetermined order, said labels beingselectively marked at a predetermined place when said order includes asignificant change, means for applying each label to a differentsignature, means for reading each label at said predetermined place todetect said seLective mark, and means responsive to a detection of saidmark for selectively identifying the label bearing said mark.
 6. Thereader of claim 5 wherein said code mark is a zip code mark and saidsignificant change is a change in a zip code.
 7. The reader of claim 6wherein said mark changes the reflectivity of said label and saidreading means comprises a photocell for detecting said change inreflectivity.
 8. The reader of claim 7 including means for conveyingsaid signatures in alignment past said reader, and said means foridentifying said label comprises means for kicking askew the signaturehaving the label bearing said mark.
 9. The sensor of claim 2 whereinsaid kicking means includes a delay circuit to postpone actuation. 10.The sensor of claim 1 wherein said scanning means includes a photocell.11. The sensor of claim 1 which includes a visual indicator responsiveto said output signal.
 12. The reader of claim 5 wherein reading meansis responsive to said conveyer means.